Control of air conditioning system with limited number of discrete inputs

ABSTRACT

A method for interpreting input on a X input multi-stage HVAC &amp; R system to control Y stages of the system wherein Y is greater than X, including the steps of receiving input from X inputs; translating the input into a binary system having Y binary outputs; and controlling the system based upon the binary outputs.

BACKGROUND OF THE INVENTION

The invention relates to heating, ventilation, air conditioning andrefrigeration (HVAC & R) systems and, more particularly to a system andmethod for operating a system which has a limited number of controlinputs.

Conventional systems may frequently have only a discrete number ofinputs which can be utilized to signify control actions of the device.For example, certain HVAC & R systems have, and can read, only twodiscrete inputs which signify the desired amount of cooling needed ordesired in a particular space. Further, third party controls andthermostats typically only have two outputs for use in issuing suchinputs to the air conditioning system. Thus, with two inputs, theconventional system must decide as to how it is to be operated.

Such systems can frequently have three or more stages or vaporcompression circuits, and when the number of stages exceeds the numberof inputs, the flexibility of operation of the device is limited.

The need exists for an improved method for operating such a system, toprovide suitable control for all possible states of operation for same.

It is therefore the primary object of the present invention to providesuch a system.

It is a further object of the present invention to provide a method foroperating a multi-stage having limited numbers of inputs so as toprovide expanded ranges of operation of same.

Other objects and advantages of the present invention will appearhereinbelow.

SUMMARY OF THE INVENTION

In accordance with the present invention, the foregoing objects andadvantages have been readily attained.

According to the invention, a method is provided for interpreting inputon an X input multi-stage HVAC & R system to control Y stages of thesystem, wherein Y is greater than X. This method comprises the steps ofreceiving input from X inputs; translating said input into a binarysystem having Y binary outputs; and controlling said system based uponsaid binary outputs.

In further accordance with the invention, an HVAC & R system is providedwhich comprises a multi-stage system having X inputs; and Y stages, andwherein Y is greater than X; and a processor adapted to receive said Xinputs, translate said X inputs into a binary system, and use saidbinary system to control said Y stages.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of preferred embodiments of the present inventionfollows, with reference to the attached FIG. 1, which schematicallyillustrates a system and method in accordance with the presentinvention.

DETAILED DESCRIPTION

The invention relates to heating, ventilation, air conditioning andrefrigeration (HVAC &R) systems and, more particularly, to such systemsand a method for operating such systems whereby limited number ofcontrol inputs can be used to independently control a greater number ofstages of the system.

FIG. 1 shows a system 10 including a multi-stage cooling system 12 and athermostat 14 which is used to control operation of multi-stage system12.

System 12 includes a plurality of stages 16, 18, 20, in this case threestages, each including a compressor and typical components of a vaporcompression circuit for providing the desired cooling function. System12 further includes a microprocessor 22 which is communicated withstages 16, 18, 20, and also with thermostat 14. Microprocessor 22advantageously serves to receive input from thermostat 14 and use thisinput to control stages 16, 18, 20 as will be further discussed below.

As identified above, thermostat 14 is frequently a device with a limitednumber of outputs, in this case labeled as y1 and y2. Further,conventional systems typically have a limited number of inputs forreceiving such input and microprocessor 22 in this invention is shownhaving a like number of inputs as the output of thermostat 14. Thus,inputs 24 of microprocessor 22 are adapted to receive output fromthermostat 14, and to translate this input into a greater number ofoutputs which can be used to more flexibly control the different stagesof system 12 as desired.

In accordance with the invention, the inputs y1, y2 are translated orconverted into a binary system which can then be used to signify arelatively greater number of different commands that can be conveyed tothe different stages of system 10.

This is more clearly illustrated in Tables 1, 2 and 3 set forth below.TABLE 1 Standard control system (Option 1) Y1 Y2 # of stages 0 0 0 1 0 10 1 3 1 1 3

TABLE 2 Standard control system (Option 2) Y1 Y2 # of stages 0 0 0 1 0 20 1 3 1 1 3

TABLE 3 Binary control system # of stages turned Y1 Y2 on by themicroprocessor 0 0 0 1 0 1 0 1 2 1 1 3

Table one shows one configuration of a conventional control systemwherein the microprocessor typically turns on the first stage of coolingwhen the y1 input is on, and turns on all stages of the system when they2 input is on. Thus, in such system, the y1, y2 inputs can be used tocontrol the system with only one or three stages active.

In a reverse of the configuration of Table 1, the y1 input can beconfigured to turn on two stages, while the y2 input turns on allstages. This provides for operation with two or three stages of thesystem active.

It should be readily apparent, however, that the configurations ofTables 1 and 2 do not allow for operation of the system with each of 0,1, 2 and 3 stages active.

In accordance with the invention, the inputs are translated into abinary control system such as that illustrated in Table 3 above wherebythe combination of different inputs has significance as well as thequantity of the input, so that the 2 signal input can be translated into4 different commands. This advantageously allows for a 2 input system tooperate with 4 of stages in operation as illustrated in Table 3, and isparticularly advantageous as compared to conventional control systems.

It should be readily appreciated that the system and method of thepresent invention can advantageously be adapted to systems having agreater number of inputs and still further greater number of stages. Forexample, a system having 3 inputs can be provided in accordance with theinvention whereby the 3 inputs are translated into 8 different distinctcommands of a binary control system so that 8 stages of cooling can beprovided. Similarly, a 4-input system can handle sixteen differentstages.

This can further be advantageously be incorporated into systems whichhave both cooling and heating capacity and stages, and preferably whichhave multiple stages of each. Under such circumstances, a limited numberof inputs can be utilized to control multiple stages of cooling,multiple stages of heating, and combinations thereof.

In such a system, for example a system having 4 inputs and 3 stages eachof heating and cooling, conventional systems cannot be used to providecompletely flexible operation of each of different stages. In accordancewith the present invention, however, and as illustrated in Table 4below, the input from stages 1 and 2, along with a third inputindicating cooling or no cooling, can be used to provide flexibleoperation of each and all stages of the system, while leaving the fourthinput advantageously available for use for a different piece ofinformation. TABLE 4 Stage Input Stage Input # of Cool # of Heating #2#1 Cooling? Stages Stages 0 0 0 0 0 0 1 0 0 1 1 0 0 0 2 1 1 0 0 3 0 0 10 0 0 1 1 1 0 1 0 1 2 0 1 1 1 3 0

Thus it should readily be appreciated that the system and method inaccordance with the present invention advantageously provide foroperation of a system having X inputs so as to independently control Ystages of the system, wherein Y is greater than X, so as to provideenhanced flexibility of operation of the system without substantialcomplication of same.

Microprocessor 22 can advantageously be any type of processor unitadvantageously adapted to be incorporated into an HVAC & R system, orcan alternatively be provided as external hardware, or as a separatedevice communicated through various electronic communication means.

Furthermore, thermostat 14 can be any type of air conditioning orbuilding control system, smart thermostat, and the like.

Still further, it should be appreciated that the system and method ofthe present invention can be incorporated into existing systems and/orincorporated into new systems, as the system and method of the presentinvention readily provide for incorporation or retrofit into existingsystems.

It is to be understood that the invention is not limited to theillustrations described and shown herein, which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare susceptible of modification of form, size, arrangement of parts anddetails of operation. The invention rather is intended to encompass allsuch modifications which are within its spirit and scope as defined bythe claims.

1. A method for interpreting input on a X input multi-stage HVAC & Rsystem to control Y stages of said system, wherein Y is greater than X,comprising the steps of: receiving input from X inputs; translating saidinput into a binary system having Y binary outputs; and controlling saidsystem based upon said binary outputs.
 2. The method of claim 1, whereinsaid system has 2 inputs and 3 stages, and wherein said binary outputsallow said system to be operated with each of 0, 1, 2 and 3 of saidstages active.
 3. The method of claim 1, wherein said stages are vaporcompression circuits.
 4. The method of claim 1, wherein said stages areadapted to provide at lest one of heating, cooling and combinationsthereof.
 5. The method of claim 1, wherein said stages include bothheating and cooling stages.
 6. An HVAC & R system, comprising: amulti-stage system having X inputs; and Y stages, and wherein Y isgreater than X; and a processor adapted to receive said X inputs,translate said X inputs into a binary system, and use said binary systemto control said Y stages.
 7. The system of claim 6, wherein said systemhas 2 inputs and 3 stages, and wherein said binary outputs allow saidsystem to be operated with each of 0, 1, 2 and 3 of said stages active.8. The system of claim 6, wherein said stages are vapor compressioncircuits.
 9. The system of claim 6, wherein said stages are adapted toprovide at lest one of heating, cooling and combinations thereof. 10.The system of claim 6, wherein said stages include both heating andcooling stages.
 11. The system of claim 6, further comprising an inputmember communicated with said system for providing said X input to saidprocessor.